It's part of Krieg's back story. He was one of the people experimented on in the Wildlife preserve, and at some point he managed to escape (not before killing a bunch of the doctors of course)That's why there's that rumor that he's Tiny Tina's father.

It's part of Krieg's back story. He was one of the people experimented on in the Wildlife preserve, and at some point he managed to escape (not before killing a bunch of the doctors of course)That's why there's that rumor that he's Tiny Tina's father.

Plus there's the recent nugget from the last Headhunter when Krieg gets an apology letter from "Sammy". It's likely that it's from Dr. Samuels, the scientist mentioned in "Doctor's Orders" as being in charge of the slag experiments, though the Krieg-speak nature of her letter brings up a possibility that she's since become the victim of her own research.